QuantArray®-Chlor during Performance Monitoring
The study site is a portion of a chemical manufacturing facility impacted by 1,1,2-trichloroethane (TCA), 1,2-dichloroethane (DCA), trichloroethene (TCE), and chloroform. During site assessment, QuantArray analysis revealed that key halorespiring bacteria including Dehalococcoides, Dehalobacter and Dehalogenimonas spp. were present. However, Dehalococcoides populations were below the 104 cells/mL recommended for effective reductive dechlorination. Therefore, biostimulation through electron donor addition was selected as the treatment option. See case study QuantArray-Chlor during Site Assessment and Remedy Selection for details.
QuantArray-Chlor Results and Interpretation
QuantArray-Chlor was routinely performed to provide a direct and timely line of evidence to assess the impact of electron donor addition on halorespiring bacterial populations. The figure below compares baseline populations (gray bars) at OW3 to concentrations of targeted halorespiring bacteria and functional genes detected 6 months after injection (light blue bars) and 12 months after injection (dark blue bars). Similar results were obtained for observation wells OSW5 and OSW5D.